Add docs in ProgressBar to suggest a11y min durations

setMinDurationBetweenContentChanges was introduced in Android 34.
ProgressBars, which frequently emit state changes due to its incrementing state, are examples of where this API can be used to prevent disruptive notifications.

Bug: 332393061
Test: na (docs)
Change-Id: Ia1b22137d3078211d23d56872af36ad20d0ce19d